A Hercules user, Peppe A.K.A. Giuseppe Vitillaro, reported an issue ongroup hercules-os380 which identified another issue.His Hercules configuration file had his initial ARCHLVL before MAINSIZE.His MAINSIZE was rejected with a message that MAINSIZE was invalid.S/370-24bit and S/370-31bit both have instructions that access 31-bit realmemory: ISKE, SSKE, RRBE, and TB.S/370-24bit and S/370-31bit both use extended IDAW for 31-bit I/O real addresses.Hercules has been trying to allow the Hercules configuration file to be scrambled.One line of code appears to break both IBM most current S/370-24bit Principles ofOperation and Hercules attempt to allow a scrambled configuration file.

Yes, paging maximum real memory use, not a real memory limit, iswhere I assUme the weird value was picked up from.IBM had room to go to 28-bit as in 256MB real memory for pagingmemory frames only but at the time didn't have the hardware tosell and didn't need to help their competition.

The 64MB could be picked for the maximum block size in a CCW ?A stand-alone dump would have to chain a CCW for more memory.I would command chain for multiple blocks on tape, but maybe that's me?Or could the 64MB be the size on my 4381-T92E memory?But the most current S370-24bit Principles of Operation makesit clear that I/O IDAW and logical addresses in instructions are limited to31-bit A.K.A. 2GB which is what is needed.

Many operating systems don't allow a user application to have over8MB for private virtual memory.I'm glad that 8MB operating system virtual memory maximum wasn't thenumber picked for the maximum architecture real memory size.I also hope that makes no sense to anyone.

The change also adding a forced Hercules configuration file order isnot good either.

There shouldn't be a restriction on MAINSIZE based on architecture(maybe a warning... but that's it). There is nothing that restricts aS/370 system from having more than 64MB of storage (only a restrictionon how much can be used).

I concur.There shouldn't be a restriction on MAINSIZE based on architecture(maybe a warning... but that's it). There is nothing that restricts aS/370 system from having more than 64MB of storage (only a restrictionon how much can be used).Furthermore, as indicated, machine configuration statement ordershouldn't be an issue (at least for backward compatibility).I think hercules should honor the storage size indicated - regardless ofthe final chosen architectural mode !--Ivan

I agree, a warning may be acceptable, a restrictionseems to much. A config parser which depends from the order,may become a nightmare.

Well, APL/360 did set an 8MiB limit. Since the actual hardware didn'treach that size for another decade after its release, that wasreasonable.Aren't you trying to create a S/380 hardware definition that includesnew features that S/370 didn't actually have?

Yes, paging maximum real memory use, not a real memory limit, iswhere I assUme the weird value was picked up from.IBM had room to go to 28-bit as in 256MB real memory for pagingmemory frames only but at the time didn't have the hardware tosell and didn't need to help their competition.The 64MB could be picked for the maximum block size in a CCW ?A stand-alone dump would have to chain a CCW for more memory.I would command chain for multiple blocks on tape, but maybe that's me?Or could the 64MB be the size on my 4381-T92E memory?But the most current S370-24bit Principles of Operation makesit clear that I/O IDAW and logical addresses in instructions are limited to31-bit A.K.A. 2GB which is what is needed.Many operating systems don't allow a user application to have over8MB for private virtual memory.I'm glad that 8MB operating system virtual memory maximum wasn't thenumber picked for the maximum architecture real memory size.I also hope that makes no sense to anyone.The change also adding a forced Hercules configuration file order isnot good either.------------------------------------------------------------------------http://groups.yahoo.com/group/hercules-390http://www.hercules-390.org------------------------------------Yahoo Groups Links

--Mike A Schwab, Springfield IL USAWhere do Forest Rangers go to get away from it all?

Post by Mike Schwab ***@gmail.com [hercules-390]Well, APL/360 did set an 8MiB limit. Since the actual hardware didn'treach that size for another decade after its release, that wasreasonable.Aren't you trying to create a S/380 hardware definition that includesnew features that S/370 didn't actually have?

That's not the issue !

The issue is :

ARCHLVL S/370MAINSIZE 128M

will fail

MAINSIZE 128MARCHLVL S/370

Will succeed !

You could have a 3090 with 128M of memory and run it in S/370 mode...(you could only use 64M though), but it worked...

Post by Ivan Warren ***@vmfacility.fr [hercules-390]That's not the issue !ARCHLVL S/370MAINSIZE 128Mwill failMAINSIZE 128MARCHLVL S/370Will succeed !You could have a 3090 with 128M of memory and run it in S/370 mode...(you could only use 64M though), but it worked...--Ivan[Non-text portions of this message have been removed]

Did you try to access real memory above 64MB on the3090 in S/370-24bit mode?Did it work or did IBM fix it or was the Principles of Operation changed?

Post by Ivan Warren ***@vmfacility.fr [hercules-390]That's not the issue !ARCHLVL S/370MAINSIZE 128Mwill failMAINSIZE 128MARCHLVL S/370Will succeed !You could have a 3090 with 128M of memory and run it in S/370 mode...(you could only use 64M though), but it worked...--Ivan[Non-text portions of this message have been removed]

Did you try to access real memory above 64MB on the3090 in S/370-24bit mode?Did it work or did IBM fix it or was the Principles of Operation changed?

That's irrelevant.. It worked in the sense that you could have aconfiguration with more than 64MB of main storage in S/370 mode (Itdidn't *fail* in the sense that you could still Power ON/IML the beast -even if you couldn't really make any use of the extra storage).

Well, APL/360 did set an 8MiB limit. Since the actual hardwaredidn't reach that size for another decade after its release,that was reasonable.Aren't you trying to create a S/380 hardware definition thatincludes new features that S/370 didn't actually have?

That's not the issue !ARCHLVL S/370MAINSIZE 128Mwill failMAINSIZE 128MARCHLVL S/370Will succeed !You could have a 3090 with 128M of memory and run it in S/370mode... (you could only use 64M though), but it worked...

Agreed. The second should fail with the same error or at least throw a warning. But again, just as I instructed somitcw, please create a new github issue for this problem so I/we can discuss/track its progress there:

Well, APL/360 did set an 8MiB limit. Since the actual hardware didn'treach that size for another decade after its release, that wasreasonable.Aren't you trying to create a S/380 hardware definition that includesnew features that S/370 didn't actually have?

- - - old notes snipped - - -

Not me. Other people are using OS/380 and theirmodified Hercules 3.07 doesn't have the bug.I've never used S/380 or tested it.

I'm just trying to fix Hercules configuration filestatement order and make ARCHLVL S370 come closeto matching the most current S/370-24bit Principles ofOperation.

If the ARCHLVL S370 PSW.32 worked like is says in theS/370-31bit Principles of Operation, I might play with it.

With a couple of changes to follow IBM's lead, S/380 couldmatch IBM systems much better, but ARCHLVL S370 willnever allow the two S/370-31bit features needed.

so I can track the problem from there. Mark's change on the face of it seems reasonable, but as Ivan wrote in a subsequent reply, there should at least be a warning when archlvl 3/370 is set to let you know the original mainsize has been changed from what you originally specified.

But again, I don't want to argue/discuss the issue here. Please create a github issue and we and anyone else can all discuss the issue there along with the merits (pros and cons) of whatever various proposed solutions we may come up with.